1. Field of the Invention
This invention relates to a zoom lens device and a method for controlling the device.
2. Description of the Related Art
In zoom lens devices, at the time of fabrication of lenses, astigmatism occurs to a degree of 0.1 in terms of Newton stripes. In the past, at the time of assembly of a zoom lens, astigmatism has been reduced (WO2012/046450A). However, in a zoom lens superior to that in a high-definition television broadcast system, in a case of continuously changing a zoom ratio, an effect of astigmatism is not negligible.